Falls affect millions of people each year and result in significant injuries, particularly in the elderly. In fact, it has been estimated that falls are one of the top three causes of death in elderly people.
A fall is defined as a sudden, uncontrolled and unintentional downward displacement of the body to the ground. There are currently some fall detection systems available that detect these falls and allow the user to obtain assistance manually or automatically if a fall occurs. Exemplary fall detection systems can comprise personal help buttons (PHBs) or worn and/or environment-based automatic detection systems.
Automatic fall detection systems comprise one or a set of sensors that continuously measure the movement of the user, and a processor that compares the measured or processed signals with predetermined thresholds in order to detect a fall. In particular, automatic fall detection systems store a set of predetermined threshold values and/or classification patterns (which are hereinafter referred to as parameter sets). When the system is activated, movement data obtained from the sensors (such as, for example, an accelerometer) will be continuously transformed and processed, and then compared with those parameter sets to determine if a fall event occurs.
Many fall detection systems also calculate a change in the orientation of the fall detection system (and hence the user) and detect an impact with the ground during a fall event.
A disadvantage of these systems is that they lack full reliability. Furthermore, they do not actually prevent falling, but provide a warning or alarm in the event that a user already has fallen.
However, users that are insecure during walking, for example caused or enhanced by a fear of falling or by fatigue in the muscles or that are frequently multi-tasking, i.e. they are carrying items when walking, talking to their grandchild, etc, or that move in places where there is dim lighting, a wet or irregular ground surface (such as loose carpet, electricity wires, toys, tools, and other hazards) or that are under medication that may affect balance or concentration can be assisted by a system for fall prevention, which decreases the actual risk of falling or at least helps them to avoid situations where there is a higher risk of falling, and makes them feel more safe.
WO 2008/059418 describes a system for fall prevention for a user, comprising a number of sensors attachable to at least one lower body segment, in which the sensors are adapted to measure movement of the at least one lower body segment and to translate the movement into a signal, the system further comprising a control adapted to receive the signal from the respective sensors, observe the signal as an actual sequence of postures of the at least one lower body segment, compare the actual sequence with a predetermined sequence of postures as a function of time (the predetermined sequence relating to a low risk of falling), and to determine a high risk of falling when the actual sequence deviates from the predetermined sequence (to a certain degree).
Thus, this system provides a way of indicating when falls are more likely to occur, with the increased risk occurring when there is a variation in the trajectory of the feet of the user.
It is an object of the invention to provide a system for fall prevention that improves on that described above.